Windows 7 and error "Could not connect to the System Event Notification Service"

At the moment I work at a company with about 8000 to 9000 workstations. A couple of users called in an issue that they had trouble logging in into Windows 7. Once in a while they got the following error message during the logon process.

“Windows could not connect to the Event Notification Service service. Please consult your System Administrator”

Only one or more reboot(s) seemed to bypass the error. This was not an acceptable situation and I was asked to look into this problem.

Environment description:

Windows 2008 R2

Window 7

SCCM 2007 R2

RES Workspace Manager 2011

App-V 4.6 SP1

Underneath a screenshot of the error message:

After checking the event viewer I noticed that not only the “System Event Notification Service” was failing but also several other services failed to start. Underneath a list of services that are involved.

Certificate Propagation

Extensible Authentication Protocol

Group Policy Client

IKE and AuthIP IPsec Keying Modules

IP Helper

Server

Multimedia Class Scheduler

User Profile Service

Task Scheduler

System Event Notification Service

Shell Hardware Detection

Themes

Windows Management Instrumentation

With the knowledge that not only the “System Event Notification Service” service was failing to start I searched the web for a solution. I found several articles but they didn’t solve my problem. Than I stumbled onto the following Hotfix:

This hotfix solved my problem. But in the meanwhile several users were still experiencing this problem. Due a backlog on the change management side, it would take a while to get this hotfix in production. I decided to look for a workaround for the customers who were experiencing this problem more frequently. It seemed, like described in the article, that the “Microsoft Virtualization client” had something to do with it. I quote:

“Cause: This issue occurs when a new drive is added to the system while background services are still starting. The most common example of this is with Microsoft Application Virtualization Client. When this service starts, it creates a virtual drive. When this drive is created during system startup, the Server service may crash the shared service host process. This process contains other services which are important for completing user logins. When these services fail at startup, a blue or black background image is displayed instead of the user’s desktop.“

When trying to find a workaround I found that delaying the startup of the “Microsoft Virtualization Client” service seemed to work. This should give the other services time to start-up. It’s a quick and dirty method but it did solve the problem for the users who were experiencing this problem on a frequent base. We decided to use it as a temporally workaround until the hotfix was applied.

The hotfix is also applicable for Windows Server 2008 R2 in case you are experiencing the same issues on a server.

I had this error and found that the COM+ System Application service was listed as a service that depended (that is, listed in the lower box under dependencies) on the System Event Notification Service, and the COM+ service was stopped. After starting this service and setting to Automatic startup the issue was fixed.

I don’t know how this service was configured before the error nor why it should suddenly be a problem but discovered the only program to update just prior to error was Rapport by Trusteer, something I use for online banking. Might just be coincidence but I have had issues with this software before.

I don’t know the program “Rapport by Trusteer” but it is possible that multiple applications could cause this issue. Haven’t looked at the COM+ service tho but it could be of some help to other people who come here.

First of all thanks :), second I’m afraid I’m not that familiar with Xenserver 5.6 and I think it needs some more troubleshooting in your case.

Here are a few things I would check for:

– Scan the event viewer log for errors on which services did not start correctly and/or check services list
– Does rebooting (maybe several times) solve the issue?
– On which OS are you running Xenserver?
– Are there applications that use/create a (virtual) drive at start up, like App-V does? If so and if it’s a service than try to delay that service, like mentioned in my workaround.

I downloaded the hotfix and started the hotfix. Thanks for the link.
Unfortunalely the Guest user is still not able to be connected to SENS – this, although whilethis service is now deactived…
If you might see a solution? I already disactiveted the user and reactivated it – something that worked in the past – but his time something got stuck bady…

Check settings in my company and changed setting of SENS to manual. And yes, the computer gets slower…

Hi Marco, I have this “Could not connect to the System Event Notification Service” problem, however, I got it slightly different with everyone else.
– All the services you mentioned above are starting in my Services
– I still have my desktop, not the blue/black background (it happened a little while in the beginning, but immediately changed to my usual desktop). But all of the usual win7 animation (idk how people call it… aero?) are disappeared. My taskbar & folders look like winXP too.
– I do can only choose ‘administrator’ option in the beginning. But I still need to ‘Run as Administrator’ when I use windows features like cmd..?

I kinda realized why this problem occurred to me, however I dont know how to fix it. I think it’s either :
– I plugged in my old external HD (i havent use it for so long) to backup my files & shutdown my pc with the extHDD still attached
– I plugged in my friend’s flashdisk that’s either damaged or broken i dont know, because it wouldnt detect in my pc
– Last week I bought a new memory-pc that’s apparently incompatible, after several times trial & error (and lots of pc restarting, pick & plug the ram etc) eventually I go back to my old RAM, but there’s something a bit wrong with my pc so I decided to use Tuneup utilities to Clean Disk, Clean Registry, Defragment Registry….. all at one go.
I do think after this on I started getting trouble with Startup (i often had to restart twice to simply get into windows) and the Administrator account start showing up even though I never set my user account in the beginning.
And then idk it looks like everything else could be triggered by the external drivers I mentioned above (extHDD & FD)

Do you think I can still use the hotfix tool? or will it make my pc goes worse?

You can still install the Hotfix if you like but I do not believe it will solve your issues. It seems like, reading your description, that most likely your Windows 7 Operating system is damaged by cleaning the registry. Tuneup Utilities is a great program but can damage your OS when wrongly used. I suggest that you create backup of your files and install Windows 7 again or try to repair your system with in the original Windows 7 dvd. Please follow this link for a step-by-step guide.

So I finally used the hotfix tool, and all my aeros are back and there’s no more “Could not connect to the System Event Notification Service” problem. However my computer is still running slow at the startup and I believe it wasn’t because of the background program that run in the desktop background. Also my Event viewer log isn’t working. I even updated my graphic card already.
The problem is I dont have CD/DVD writer in my cpu and I got my win7 installed from the store where I bought my pc 1 year ago. I guess I will find another way….

For work I needed to analyze slow performance and therefore was using a script which rebooted the computer a 100 times with autologon.
As I was performing this task with remote desktop I didn’t see the error you described.
All we noticed was that all of a sudden the script ended and there and we couldn’t find a patern in it for troubleshooting,
I’ve tried the hotfix and the script is still running succesfully.

Thank you for this great pointer!
I saved it as the “NuijensFix” should I come to other weird challenges at work. 🙂

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